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Discussion Starter · #1 ·
Hey guys I have had issues all year with intake leaks and cant seem to seal it properly.
I have a 74 ironhead with a s&s super e carb. I have my manifold on with o rings and clamps. before that I had the clamps and rubber bands, but o rings seemed to be better. I also have good carb supports off my manifold from the top and bottom.
any tips? I was told maybe o rings then a strip of electrical tape then camps???
 

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You may be overtightening the clamps. which can distort o rings and rubbers, causing leaks.
 

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Discussion Starter · #3 ·
so just snugg the orings up??
I was told the bands cant be to tight but the orings need to be
 

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Take carb off and run your finger around the inside of manifold where heads meet to see if it feels like theres no alignment issues there,your cylinders may need to be loosend of a bit and given a bit of a twist,i have o-rings and bands on my iron.
 

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you can make an adapter to fit onto the carb's manifold
then hook it up to a bicycle pump and test to see actually where you're leaking with soap+water

I can't think of another way that's not a complete crap shoot to find where the leaks are at
(I'm dealing with this on my ironhead now too)
 

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Take carb off and run your finger around the inside of manifold where heads meet to see if it feels like theres no alignment issues there,your cylinders may need to be loosend of a bit and given a bit of a twist,i have o-rings and bands on my iron.
If you want to replace the head gaskets, this will work. It should be done that way, when installing the heads. But if you loosen the heads enough to align the intake to match, you will end up blowing your head gaskets, unless you are super lucky.

My old school fix, beside the above mention of a plate mounted to the intake, pressure and soapy water, is this. Remove carb, remove intake. Stick intake up to heads, and see how it matches the two intakes on the heads. If it is real close, you are ready to install everything. I am assuming that the oring bosses are in excellent shape, on the heads and the intake. Plus, no mismatched heads to intake, ie: oring heads and band style intake. Buy some oil resistant silicone. Soak the orings in silicone and install on intake/head, with clamps. Take a fingerfull of silicone and wipe inside the intake, at the oring connection. Rub in the groove really good, and then, wipe clean, caring NOT to remove the silicone in the groove. Usually best to wipe pretty clean, and then wait until it drys and rub with your finger to get the rest out. Make sure the carb to intake flanges are clean, and the carb oring is good. I usually run a gasket too, just incase. Make sure the carb is sitting pretty level, with the motor standing up straight. Then make sure the carb support is not "pinching the carb up or down. Yes, when running the orings, you need them tight. But, remember to use the hose clamp style clamps, not those fancy two piece ones, that neve seem to get tight enough, with a oring style intake.
 

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another idea, make sure your mounts aren't pulling your carb away from the heads' intake ports

my stupid ass was tightening the 1 carb mount I had (connected to the front intake push rod) and it was pulling the carb away from the engine just enough so that I got a small leak
 

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Discussion Starter · #9 ·
thanks for all the info guys. Im gunna get new orings and clamps and make sure everything is snug and use silicone. if i need to lossen the juggs i will get a new gaskets!
 

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you can make an adapter to fit onto the carb's manifold
then hook it up to a bicycle pump and test to see actually where you're leaking with soap+water

I can't think of another way that's not a complete crap shoot to find where the leaks are at
(I'm dealing with this on my ironhead now too)
Pusher!

You almost got it right!

Unfortunately, a lot of people miss smaller leaks when using a hand pump, or even 12v mattress pumps.
Many micro leaks will only display themselves as tiny blisters of foam with at least a half a minute of a constant, regulated supply of air.

Even the tiniest of leaks affect tuning and performance.

....Cotten
 

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And the alcohol in the gas will clean out the rest!

....Cotten
Another way of saying -- don't count on silicone or silicone grease to do any long term sealing. But, it may help your o-rings to wiggle and squirm around a little more as you are snugging your clamps :D.
 

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Pusher!

You almost got it right!

Unfortunately, a lot of people miss smaller leaks when using a hand pump, or even 12v mattress pumps.
Many micro leaks will only display themselves as tiny blisters of foam with at least a half a minute of a constant, regulated supply of air.

Even the tiniest of leaks affect tuning and performance.

....Cotten
Cotten,
Do you ever add input, or do you just criticize others? ?? I'm starting to think Sinner is on to something. As intelligent as you seem to be, one would think you would have figured it out by now. It was said to me as a child, "if you have nothing to add that will be benificial, kindly keep your opinions to yourself."

As for the leak , i have had many, all of which where a combination of poor cylinder/head alignment & cheap shitty clamps. I have in the past run band style clamps & bands over o-rings to get me where i needed to able to get head gaskets & do a proper allignment of the heads & intake. I was also told,"There's never enough time to do it right, but there's always time to do it again. " !!!!!!!
 

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Cotten,
Do you ever add input, or do you just criticize others? ?? I'm starting to think Sinner is on to something. As intelligent as you seem to be, one would think you would have figured it out by now. It was said to me as a child, "if you have nothing to add that will be benificial, kindly keep your opinions to yourself."

As for the leak , i have had many, all of which where a combination of poor cylinder/head alignment & cheap shitty clamps. I have in the past run band style clamps & bands over o-rings to get me where i needed to able to get head gaskets & do a proper allignment of the heads & intake. I was also told,"There's never enough time to do it right, but there's always time to do it again. " !!!!!!!
Sorry you took it personal Slim,

But a handpump still doesn't cut it.

Its about fixing it right, Folks.
A missed leak means grief,.. sooner, or later.

If you don't like my style, Slim, I'll start dressing in drag just for you.

...Cotten
 

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Sweet !!! I love red heads !!! With hairy legs !!! LOL
 

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One thing that seems to be missed is the bracket that goes from the back of the air cleaner to the case to make sure the carb is secure. I had issues with my '74 when I omitted the bracket when I got a new air cleaner and after figuring that out, replaced it and all was well. It will keep the carb from wanting to droop down from the weight. Just a thought. :cool:
 

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Discussion Starter · #18 ·
see im running a very small benchmark aircleaner and just made a mount from top motormount to the intake manif. and one at the bottom of intake to bottom of the juggs. I also ran a s&s aircleaner with the mount on air cleaner and it was not as good/strong as the manifold mounts.

cotten, do you any pointers, is their somthing im missing?? I agree that even tiny leaks can be bad for performance.
 

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Jessee!

Heavy Clutch's tip is important.
I use a hammer handle in the mouth of the manifold to hold it while I fiddle with the clamps, then pull it out and feel the alignment with my finger.
Sometimes inverting the manifold helps get a better alignment, I don't know why.

All assembly is clean and dry of any sealers, etc.

With the clamps only snug enough to hold it, I then put on the testplate and squirt for leaks as I slowly tighten and tweak and massage the assembly to find its "sweet spot" where it seals. Then I firm up the clamps while testing, to be certain not to over-tighten.

The clamps should be OEM-style with #10 fasteners, not 1/4".
Beware of some stainless varieties that must be shaved down to an even .750" from their metric width.

Once secure and bubble-free, the supports should be tweaked to where there is no stress or bind to mate up the carburetor.

Beyond that, I am afraid that you are at the mercy of your own patience and powers of observation. Beware that even modern S&S manifolds have displayed casting porosities in places un-imagineable.

To keep an assembly secure with today's P4gas, I strongly suggest viton O-rings such as are available from JAMES.

Good luck,

....Cotten
 
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